The invention relates to a mechanical lifting mechanism wherein lift is accomplished through a continuous cyclic succession of vertical reciprocation. The invention is particularly related to a mechanism for vertical reciprocation involved in the pumped recovery of oil or water from a well casing.
Systems for developing a reciprocating motion in oil well pumps are known, e.g. from U.S. Pat. Nos. 2,171,171 (Braver) 4,848,085 (Rosman), 4,480,685 (Gilbertson) and other prior art references. These mechanisms are usually heavy for convenient transportation and they often require a complex operation control system which may render the operation unreliable. They also have a high energy consumption.
It is an object of the invention to improve the pumping systems available and in particular to reduce the size of the pumping units, to decrease the power demand needed to operate these units, to increase the operational reliability and reduce the space required to set up these units.
Another specific object is to eliminate the need for a derrick or pressure counter weight to support the pumping unit and to eliminate the need for any structure substantially taller than the stroke of the pump.